The actual display of your <div> will very depending on whether or not it's parent container (<div>) also has a declared position.

That is, if it's parent container DOES NOT also have a declared position, the child <div> will do 1 of 2 things.If position:relative, it will position as desired but space will be left as though that element was still in the natural flow. So you may move the 500 X 100 element down and over, but a 500 X 100 space will be left, as though it was still there.If position:absolute, child is positioned relative to browser window and that position does not change even if window contracts or expands.

So be sure to give a declared position to both the parent and the child <div>.Best wishes,